[Please don't reply to this comment. This is so you can get the gist of what is going on.]

Nightmare here is actually some kind of snake deity responsible for turning some of the gods and goddesses (who will be mentioned in the story) into stone. Most humans and monsters alike were terrified of doing anything repeatedly wrong, because they're aware that if they did, they'd suffer the same fate.

However, some people started to disregard the warnings and started doing whatever they pleased because the legend was thought to be a scare tactic.

Scary T^T

Mackenzie: (Sleeping)

Nightmare: ….

Mackenzie: (Is woken up by Nightmare)

Nightmare: ..

Mackenzie: ?!

Nightmare: .

A FEW MINUTES LATER..
Mackenzie: (Wrapping some of the neighbors' trees in TP)

Nightmare: …

Bubbles: (Refusing to mess with the neighbors)

??: …?

Bubbles: (Giving ?? the face of "Mackenzie dragged me into this.")

??: .

LATER THAT NIGHT..
(Everyone's asleep)

Nightmare: *awake* ….

(Mackenzie ended up causing too much trouble)

??: …

(If it makes you feel better, you and Cross don't have to face Nightmare here, because you're not really in this one.)

Roberto: Hey Bubbles! Me and the others are going to be having a stayover. Wanna come with?
Bubbles: (Nods)

Nightmare: ….

THAT NIGHT..
(Evan is telling the story of Nightmare to everyone)
Evan: You know the island out at sea? It's called Mac Lir. It's called that because it's not an island at all, it's a huge giant!
Roberto: No way.
Evan: Way. Mac Lir ended up doing something the child didn't like, and gotten turned into stone! That was the Nightmare's first victim and he hasn't stopped since. To this day, most of the townsfolk are afraid to cause too much trouble, knowing that they would share Mac Lir's fate.

Nightmare mind: hmm..

Bubbles: (Scared)
Mackenzie: Nope, that's baloney.

Nightmare: ..

Mackenzie: Anyway, who's down for a little nighttime mischief?

Nightmare: ….

Bubbles: I-I'm not..
Mackenzie: Well, you're going with us anyway.

Nightmare: *fell asleep for a bit*